'rpm -q' exit value

[Toralf Lund <toralf procaptura com>]

[ Note: This is a repost of a message that may have been blocked due to 
errors in our DNS setup. I appologise if you have received it earlier. ]

I have found that at least on some rpm versions,

rpm -q <package list>

will return (as exit value) the number of packages in <package list>
that are *not* installed. Is this defined behaviour that I can rely on?
On other words, can I assume in scripts etc. that I will always get this
behaviour, regardless of rpm version.

- Toralf